Abstract: Prototyping of subsystem and system components is most often thought of as a development task. This paper shows the usefulness of prototyping as an activity in the requirements elicitation process, prior to any developement activities. It is approached from the field of engineering and technology management. It uses the Requirements Engineering approach to identify tools and methods for the development of the requirements for an underground unmanned aerial system for use in South Africa’s’ gold mines to inspect box-holes and ore-passes. Box-holes and ore-passes are vertical tunnels through which the ore must pass in moving from the stope, where it is mined, to the shaft, where it is hauled to the surface for processing. The more familiar new product development framework is compared to the requirement engineering process. The prototypes of a number of subsystems are presented, namely, a quadrotor platform, a platform preservation sensor array, an optical flow sensor for position holding, a vision sensor for operator visualization, and an operator interface. The perceived significant technological challenges are discussed as motivation in the choice of these subsystem prototypes that will be used in the interviews that are to form the basis of the requirements elicitation activity.